Locomotive fuse



LOCOMOTIVE FUSE riled Sept, 7, 1927 lml val/Zia INVENTOR Jerome 50/7070 TORNEY Patented Feb. 19, 1929.

UNITED STATES JEROME swims, or WILKINSI 'rownsnir, ALLEGHENY COUNTY, PENNSYLVANIA,

ASSIGNOB TO WESTINGHOUSE ELECTBIC- 8o PORATION OF PENNSYLVANIA.

MANUFACTURING COMPANY, A COR- LOCOMOTTVE FUSE.

Application filed September 7, 1927. Serial No. 218,041.

My invention relates to fuses, and partic ularly to fuses of the expulsion type wherein one end of the fuse-casing is open and from which the gases incident to the rupture of the fuse is discharged.

An object of myinvention isto provide an expulsion fuse wherein the closure for one end of the fuse casing constitutes a clamping. terminal wherein good conductive contact is insured.

Another object of my invention is. to "provide an expulsion fuse wherein the fusible element is provided with a terminal disc that may be securely clamped upon a terminal seat by means of athreaded closure plug or cap and wherein the fusible element is prov ded at its outer end with a weakened section or terminal that is attached to the fusible strip with a solder having a low melting point, the connection being of such character that it is severed by the heated gases incident to the rupture of the inner end of the fuse, thereby facilitating the expulsion of the fusible elewherein,

ment from the casing.

A. further object of my invention isto provide an expulsion fuse having the above noted;- characteristics. wherein the fusible element is provided with a portion having reduced current carrying capacity to insure initial rupture of the fuse at a point near the enclosed end of the casing and to provide such a fusible element with an outer terminal that is soldered thereto, and which is severed from the fuse strip by the heated gases incident to the rupture of the fuse.

These and other'objects that will be made apparent throughout the further description 0 my invention are attained by means of the fuse apparatus hereinafter described and illustrated in the accompanying drawings,

Figure 1 is an elevational view of an expulsion fuse embodying features of my invention,

Figure 2 is an end view of the fuse shown in 1 i A Figure 3 is a longitudinal section through the fuse shown in Fig. 1,

Figure 4 is a transverse section taken on the line IV-IV of Fig. 3,

Figure 5 is a perspective viewof a fragment of the fuse element. and

Fi re 6 is a perspective view of a modified orm of fusible refill.

ture of the fuse near .Referring to the drawing, the fuse comprises an insulating tubular casin 6 that is rovided at one end with an interna ly threaded ferrule 7 having an annular contact seat 8 for receiving the terminal of a. fuse element. The fuse element comprises a terminal disc 9 to which a fusible strip 11, preferably made of zinc, is attached by means of a rivet 12. The end of the fusible strip 11 near the terminal disc 9 is provided with a hole 13 for reducing the current carrying capacity of the fuse strip at this point and for insuring initial rupthe inner end thereof. The terminal disc 9 is mounted .upon the contact seat 8 of the ferrule 7 and is clamped A in conductive engagement therewith by means of a threaded closure plug 14 which is screwed into the threaded portion of the ferrule 7 and into engagement with the outer face of the disc 9, thereby securely clamping the disc in operative position. The plug 14. is provided with a slot for receiving a screw driver or other implement for turning the plug.

' The outer lower end of the casing 6 is I provided with a terminal sleeve 16 having a terminal seat 17 for receiving the outer terminal of the fuse strip 11. The outer terminal comprises a metal strip 18 preferably made of copper and which is non-fusible under ordinary operating temperatures. .The copper strip is secured to the outer end of the fuse strip 11 by means of a solder fusible at relatively low temperatures, the purpose being to provide a connection that will be sev-. ered by the heated gases incident to the rup ture of the inner end of the fuse. It will be understood that the soldered joint is of greater current carrying capacity than the reduced portion of the fuse at the hole 13 and the fuse will not be ordinarily severed at the soldered joint by reason of current passing therethrough.

.In Fig. 6 I have shown a modified form of fusible element or refill wherein the stripv is provided with a hole 10 smaller than the hole 13 that causes fusion at that point after the element fails at carrying capacity of the element adjacent the hole 10 is greater than that adjacent the hole 13. The inner end of the element is bent to form a. contact terminal, the element being adapted to be inserted thr'gugh a slot a flat contact disc.

the hole 13. The current minal strip outer casing It has been found that fuses of the expulsion type having no facilities for; severing them adjacent the open end atthe time of rupture, sometimes remain cause abnormal continuation of the arc. This is particularly true where the fuse has been ruptured under overload conditions and wherein the explosion is not as violentas is.

.which-are expelled by the gases incident to the rupture of the fuse, such casings being open at both ends and supported within the means of the fuse element which is bent-across the outer end thereof and I secured to an outer terminal. The auxiliary casing serves to elongate the insulated barrier-between the inside terminal and the exterior terminal when rupture occurs.

An auxiliary insulating: tube 19 is provided within the casing 6, for the above mentioned purpose, but in order to facilitate the rapid ex ulsion of the tube 19, the outer end of the tu e 19 is provided with an insulating bushing 21, that partially closes the outer end of the tube. The bushing is provided with a central opening 22 through whichithe ter- 18 extends'into the casing, the point of joinder with the end ofthe fusible strip being located directly above the bushing 21 in order that the point of joinder is located at a point of highest concentration of the escaping gases. The instant the fuse ruptures, the gases are discharged from the casing, carrying with it the auxiliary casing 19. The heated gases. immediately sever the fuse strip from the terminal 18 which at this time is moving downward-with the auxiliary casing after initial rupture of the fuse strip at its inner end.

The terminal strip 18 is clamped to the contact seat 17 by means of a plate 23 that is detachablysecured to the clamping seat 17 by means of screws 24. v y The expulsion fuseabove. described is supported vertically upon air-insulating base 25 that may be attached to any desired support. The base 25 is provided with contact'clips or jaws 26 and 27 in which the f se casing is detachably mounted. The clip'2 is secured to the contact jaw 26- and extends over the in'the casing and modifications,

' extends and having a restricted the casing,

closed end of the casing for preventing the recoil incident to the explosion of the fuse from longitudinally displacing the casing out of the clips.

By reason of the terminal constructions above described, the removal and replacement of a fuse element is greatly facilitated and because of the construction of the fuse strip, the operation of the fuse element is im-' proved under both overload and short circuit conditions.

WVhile I have illustrated but one embodiment of my invention, it will be apparent to those skilled in the art that various changes, substitutions, additions and omissions may be made in the apparatus illustrated without departing from the spirit and scope of my invention, as set forth in theappended claims.

I claim as my invention:

1. An expulsion fuse comprising a casing closed at one end, a fuse strip extending through'the casing and having a portion: for initiating'rupture thereof near the closed end of thec'asing, an auxiliary casing-within the first'casing through which the fuse strip opening adj acent its outer end, the said fuse strip aving a terminal adjacent the open end of the cas ing attached thereto by solder fusible by the gases incident to rupture of the said portion and extending exteriorly of the casing.

2. An expulsion fuse comprising a casing closed at one end, a fuse strip extending through the casing and having a portion for initiating rupture thereof near the closed end ofthe casing, in the first casing through which the fuse stripextends and havin a restricted opening adjacent its outer end, the said fuse strip having a terminal adjacent the ope'n'end of attached thereto by solder fusible by the gases incident to rupture of the said an auxiliary casing with portion and extending exteriorly of the cas- I ing and supporting the auxiliary casing.

3. An expulsion fuse comprising a tubular casing closed at one end, an auxiliary tubular casing within the'first casing and having its outer. end partially closed ment connected to a terminal near the-closed end .of the casing and extending through the auxiliary casing: and projecting through the outer end thereof into engagement with a to terminal, the said fusible e ement serving releasably support the said auxiliary casing.

In testimony whereof, I have hereunto subscri ped my name this 29th day of August, 192 i JEROME SANDIN.

and a fusible ele- 

